Sander valve



' Gttomegs March 31, 1936. c. A. CAMPBELL SANDER VALVE Filed March 19, 1934 N LO chamber. This is conducive to more evenly susencloses two axially aligned cylinders 24 and 25 traps;

1p ation position.

Patented M"; ls 2,035,533

UNITED STATES PAT was;

Charles A. Campbell, Watertown, N. Y.,; assignor to TheNew York Air Brake Company, a corporationof New Jersey Application ma 1a, 1934, Serial No. 716,386

20 Claims. (cl. 291-15). 7 V This invention relates to track sanders, and andhasathrust disk I! in contact with the upper ENT OFFICE particularly to valve mechanism for controlling face of the diaphragm.

the supply of air-to pneumatically actuated sand When diaphragm I2 is flexed upward valveT h k is unseated and main reservoir air flows directly One object of the invention is to provide for to the sand traps and operates them in the usual 5 sustained sanding over a definite time period. manner,

Another object is to ensure this type of .operav A passage i8 and, pipe I! connect chamber tion where the motive air for sanding is drawn ll with passage 2! in body 22 of the controlling directly from the main reservoir or simflar source, valve. a

and not from a secondary reservoir or measuring Body 22 is provided with attaching lugs 23 and 10 tained operation. connected by a' coaxial bore 26 which serves as Another object ofthe invention is to secure a chamber for a balanced piston valve oi the automatic sanding by the motion 01' an auto: inside (111ml! type- T v v pri w matic or other application valve to emergency heads 21 and 28 and a connecting reduced perapplication position, and to terminate this sandtion 2!; ,The heads .21 and 28 are freely slidable ing after a definite time interval even' though in bore 26 and areprovided with suitable leakage the application valve remains in emergency apresistance means, suchas the grooves shown.

V Attached to the end of head 21 is a piston Si Another object is to provide simple means asworking in cylinder 24 andattached to the end sociated with the timed sander to permit sanding of head 28 is a similar piston 32 working in cyl at will, such means preferably being rendered indel? Cylinder 25 1188 a ypass groove 33 in- ,main reservoir or other source or compressed "tioninoperative when timed sanding is in progress. tended to equalize the pressures on the two faces The preferred embodiment of the invention is of the piston 32 as the piston moves to the left illustrated in the accompanying drawing, in and slightly before head 28 blanks port 41, here- 25 which the single figure is a view partlyin section described. The two pistons are cupand partly in elevation, of the sander valve, shaped and present outwardly extending flanges mechanism and associated parts. a which seat on gaskets to seal the respective pis- In the drawing, 2 is a pipe leading from the tons when at their respective outer limits 01. mo-

air. A branch oi pipe'2 leads to the chamber The e d 0! cylinder 24 is closed by a can 3 3 in body I of thesander relay -valve. In cham-, with gasket 25. which not y 88818 h ap,

' r l is mounted a ported bushing I having but alsoserves as aseat for the rim of piston These may be of any" suita 1e type, but preferably face of the diaphragm.

97 seat rim 6, on.which a rubber poppet-valv I 3|. Slidable in cap 34 is a push button element seats.

The bushing! isretainedinplace and chamber is sealed by a'removable closure cap a, head j m g ou & con camp on which also serves as a. seat for the-coil compressuch 9 resisted Y r9581 slon spring Il'reacting between piston 32 and cap 7 .when 1 is mm m m 28. Cap 3! is vented to atmosphere at "but 40 flowstopassagelll which leadstothe'sand'trap's. 'Muons a gasket agaiPst'wmch the rim piston 32 seals when at its outer limit of motion.

are of the known type ha us a cleaning at and :f under a venteda sanding jet with automatic valve means for delivering an initialimomentary blast to the and piston assembly at least far enough to cause is fully exposed by head 21when in itsleit- Planing h m none position, At such time the clearance reopen valve], apnessure motoris incorpoaimmd theMwedpomdn f em n rated km j M connection to'port 44 and thence byway ot'pipe clamped 1 to by .lltoaclomvohmeortimingchamber-ll; Port 50 ii, there being amotor chamber ll within'cap 4 m m t it t m' d.

liinwhich'fluidreacts'on the lower m m a;

The above the 7 when thevalvelias beeniorced tofthe right far face is vented to. atmosnliere at II. A enoughi'orheadflto closeport 43, head 2. starts rod I is guided in a l l toexpose portll'whichleads to-the spaceat the '55 II which, when pushed clear in, shifts the valve 35 v Themain reservoir'pipe 2, leads to a port 1 branch of passage 2|.

left of piston 32. The admission of air from chamber 46 against piston 32 causes the piston to move its full stroke to the right, in which limiting position head 28 exposes port 48, leading by way of passage 2|, pipe l9, and passage II to chamber l4 of the sander valve motor.

Passage 2| is vented to atmosphere through a removable choke 49. The relation of the size of the choke 49 to the volume of the timing chamber 4 determines the duration of timed sanding.

The space to the left of piston 2| is connected by passage 5! and pipe 52 to the body of a brake application valve 53. This application valve 53 may be of the manually actuated type, but is here assumed to be of the automatic type, operable by the functioning of a deadman valve. So far as the present invention is concerned it is essential merely that the application valve have an emergency position, in which position it admits air under pressure into pipe 52.

When head 21 exposes main reservoir port 43, this communicates with a port 54, but this port is blanked by head 21 in the right hand position of the valve. Port 54 leads to the seat of a balanced piston valve 55, the lower head of which normally blanks port 54. When valve 55 is forced downward a reduced portion 58 of the valve connects port 54 and port 51 which communicates with a Button 58 limits the depression of valve 55 and the coil compression spring 59 restores the valve to closed position when released. A vented spring seat ii encloses and sustains the spring.

Operation Manual sanding without timing- 1f button 58 be depressed main reservoir air flows via 2, 43, 54, 50, 51, 2|, i0, ll to chamber l4, forcing up diaphragm l2 and unseating valve 1. When the button is released spring 59 restores valve 55, choke 4i relieves the pressure on diaphragm I2, and valve 1 closes.

Manual sanding with timing.-The operator presses button it inward partially shifting the piston and valve assembly. As soon as head 28 uncovers port 41 air pressure admitted against piston 22 snaps the piston to the right against Basket 4i. Button 3' remains in. Pressures in chambers 4, l4 and cylinder 25 to the left of piston 32, equalize and diaphragm l2 rises and holds valve I open.

The pressure fluid in the spaces just defined bleeds slowly away through choke 49 and after a period dependent on the volume of chamber 46 and size of choke 4!, the piston 32 will start to the left under the urge of spring 31. Shortly before head 2| closes port 41 piston 32 is bridged by bypass groove 8: which vents the pressure to the left of piston I2; I'hereupon the piston andv valve assembly moves rapidly to the left, restoring button 36. Until it is reset port 54 is blanked and valve 55 is rendered inoperative because deprived of an air supply.

The sanding period may readily be given any desired duration, but 30 seconds is typical.

Timed sanding in emergency.-I'f the brake application valve is moved to emergency position motive fluid is admitted against piston 3i, forcing ittothe-right. Sanding will occur as already An important p ct of the invention is'the fact that sanding air is taker-directly from the main reservoir and the timing operation does not limit the quantity nor aifect the maintained pressure of the air used in the sanding operation.

Various possible modifications within the scope of the invention are contemplated. Pistons and diaphragms are generally interchangeable. Other yielding devices may be substituted for springs, while various valve structures may be devised to control the timing of a. plurality of flows. By availing of such substitutions the actual structure may be considerably varied.

What is claimed is:

1.' In a sanding device, the combination of a main source of operating air; a normally closed valve controlling the entire flow of air from said source to a sander; means for opening said valve;

and automatic means for closing said valve and thus terminating the operation of the sander after a definite time interval.

2. In a sanding device, the combination of a main source of operating air; a normally closed valve controlling the entire flow of air from said source to a sander; manually set means for opening said valve; and automatic means for closing said valve and thus terminating the operation of the sander after a definite time interval.

3. In a sanding device, the combination of a main source of operating air; a normally closed valve controlling the entire flow of air from said source to a sander; a motor; means set by the energization of said motor to open said valve; 9. brake-applying valve having an emergency position in which it energizes said motor; and automatic means for closing said valve and thus terminating the operation of the sander after a deflnite time interval irrespective of the state of energization of the motor.

4. The combination of a sander valve controlling the flow of air to a sander; a timing reservoir;

' an expansible chamber motor having a reversely shiftable element; a timing valve arranged to shift with said element, said timing valve having a normal position in which it establishes a-charging connection for said reservoir, and an abnormal position in which it closes said connection, connects said reservoir and motor and vents motive fluid therefrom; means effective in the abnormal position of the timing valve to open the sanding valve; yielding means urging the timing valve toward normal position; and means for shifting the timing valve to abnormal position.

5. Thecombination of a sander valve controlling the flow of air to a sander; a timing reservoir; an expansible chamber motor having a reversely shiftable element; a timing valve arranged to shift with said element, said timing valve having a normal position in which it establishes a charging connection for said reservoir, and an abnormal position in which it closes said connection, connects said reservoir and motor and vents motive fluid therefrom; means eil'ective in the abnormal position ofthe timing valve to open the sanding valve; yielding means urging the timing valve .toward normal position; a pressure motorfor shifting the timing valve to abnormal position; and a brake application valvehaving an application position in which it admits motive fluid to the last-named motor.

6. The combination of a-sander valve control? ling the flow of air to a sander; a timing reservoir an expansible chamber motor having a reversely shiftable elements a timing valve arranged to shift with said element, said timing valve having aossisss a normal position in which it establishes a charging connection for said reservoir, and an abnormal valve; yielding means urging thetimin'gvalve toward normal position; a pressure-motor for shifting the timing valvetoabnormal position; a brake application. valve having an application position in which it admits motive" nuid'to -tne' last-named motor; and operable means for.shifting said timing valve to abnormal'position.- I

7. The combination of a valve for cont trolling the flow .ot motive-fluid to afsander; a

timing reservoir; a motor comprislnga..ciriinder,

a piston and. means for equalizing: on opposite sides of the pistonat one-end o! the pistonstroke; a timing valve connectedto shift with saidpiston, said timingvalve having a normal position in which said equalizing m an 18 r.

' tive and said valve establishes a charging connection to said reservoir, andan abnormal position in which said equalizing means is inefl'ective and the valve. closes said charging connection and directs pressure fluid from said reservoir against said piston and slowly vents said reservoir; means eflectivein said abnormal position of the timing valve toopen the sanding valve; yielding means urging the timing valve tonormal position; and

I normal position.

means for shifting the timing 8. The combination of a. sanding valve for controlling the flow of motive fluid toe-sander; a timing reservoir; amotorc'omprlsing a" cylinder,

a-piston and means for equalizing pressures on oppodte sides ofthe piston at one end of the piston stroke; a timing valve connectedto. shift with saidpiston; said timing valve having a nor- 1 mal'position in'wmch said equalizing Sh aeffective and said valve. establishes a charging connection to said reservoir, and an abnormal position in which said equalizing means is ineftion of the timing valve to open the sanding valve; yielding means urging the timing valve to 1 normal position; a pressure motor for shifting the timing valve to abnormal position; and a brake application valve having an application-position in which it motive fluidto the last-named motor. I

9; The combination of a-sanding valve foncon- Q trolling the flow of motive fluid to a sander; a

timing reservoir; a motor comprising a cylinder,

a piston and means for equalizing pressures on opposite sides of the piston at one end of the piston stroke; atiming valve connected to shift with said piston, said timing valve having a' normal position'in' which said equalizing .means .is effective and said valve establishes a charging connection to said reservoir, and-an abnormal position in which said equalizing means -is m effective and the valvecloses said charging connection and directs pr'essure'lluid from said resj-.

ervoir against said piston and slowly vents and reservoir; means efl'ective in said abnormal position of the timing-valve to open-the 'sandin valve; yieldingmeans urging the timing valve to==normal position;=a pressure motor for shifting the timing valve to abnormal position; a brake .applicatio valve having an application posivalve toward ab-I the-former.

14. .The combination of a normally closed 7 shifts, saidvalve having.

tion'in which'it admits motive fluidto the last-named motor; and manually operable means for shifting said timing valve to abnormal position. Y

10. The combination of a sander vaive conytrolling th'e flow of air to a sander; a timing.res-

', ervoir; an expansible chamber motor having a 're'vei sely shiftable element; atlming valve arranged to shift with said element, said valve having a normal podtion in which it es- 1o tablishes a chargingconnection for-said reservoir; and an abnormal position in which it closes saidconnection, connects said reservoir and motor and vents motor fluidtherefrom; means effective in" the abnormal position of the timing valve to open the sanding valvefyielding means urging the timing valve towardnor nal position; means for shifting the timing valve-to abnormal position; independent meansfor opening said sanding valve; and means eifective. in the abnormal position of the timing valve for rendering said independent means inoperative.

11. 'The combination oi'a sander valve con- 1 trolling the flow of air to a sanderratiming reservoir; an expansible chamber motor having- 'a reversely shiftable element; a timing valve ar- I ranged to shift with said.element.- said timing valve having a normal position in which it establishes 'a charging connection for said reservoir, and an abnormal position in which it closes said '80 connection, connects said reservoir and motorand vents motor fluid therefrom: means eifective'in the abnormal position of the timing valve to open the sanding valve; yielding means urg-. ing the timing valve toward normal position; a pressure motor for shifting .the timing valve to abnormal position: a brake application valve hav- -ing an application position in which it admits motive fluid to the last-named motor; and means for shifting position.-

12. The combinations! a normally. closed sand- 7 er valve; a fluid pressure motor foropening the same; an admission valve for admitting motive fluid to said motor; yielding means for-closing 4d said admission valve; timing means controlling closing motion of. said admission valve; a second admission valve for admitting motive fluid to saidmotor; means urging said-second valve in a closing direction; and means associated with so theflrst'admission valve, and effective-iii the open position thereof 'for precluding the supply of motive fluid to said motor through the second admission valve.

'- 13. The combination of a'normally closed sandcivalve; a fluid pressure motor for opening the same; an admission valve for admitting motive fluid to said motorpyielding means for closing 7 said admission valve; timing means controlling closing'motion of said admission valve: a second 60 admission valve for admitting motive fluid to said motor; means urging said second valve in e a closing direction; normally open supervisory valve 'means connected in series with. the second admissiiiin valve to control the flow of motive 65 fluid: and operative connections between the first admission valve and-said supervisory valve forclosing the iatterby theopening movementlof sander valve; a fluid pressure motorfor open--. ing the-same; a reservoir; a piston; a spring urging said piston toward a normal-posi tionya valve connected to shift as said piston a. normal the timing valve toward abnormal "4b position n is which it establishes a charging connection to said reservoir, and an abnormal position in which it admits pressure fluid from said reservoir to said motor and against said piston in opposition to said spring and gradually vents said reservoir; and means for shifting said valve to the last named position.

15. In a sanding device, the combination of a main source of operating air; a normally closed valve which when opened permits flow of air from said source to a sander; two controlling means each operable to open said valve; means for restoring each of said controlling means to inactive condition; and timing means serving to delay such restoration of one of said controlling means.

16. In a sanding device, the combination of a main source of operating air; a normally closed valve which when'opened permits a flow of air from said source to a sander; manually operable controlling means for holding said valve open at will; a second controlling means operable to open said valve; and timing means rendered active upon the opening of said valve by the second controlling means, and serving after a definite time interval. to suspend the valve op'ening action 01' said second controlling means.

17. In a sanding device, the combination of a main source of operating air; a normally closed valve which when opened permits a flow of air from said source to a sander; manually operable controlling means for holding; said valve'open at will; a second controlling means operable to open said valve; and timing means rendered active upon the opening of said valve by the second controlling means to retain said controlling means in active position for a definite period, and then restore it'to inactive position, and serving independently of the restoration of said controlling means to suspend the valve opening action thereof.

18. In a sanding device, the combination of a main source of operating air; a normally closed valve which when opened permits a flow of air from said source to a sander; a controlling means for said valve having a normal inactive position,

and an active position in which it holdssaid valve open; two actuators for said controlling means, one actuator being manually operated and the other power operated; and timing means rendered active upon the opening of said valve by said controlling means to retain the controlling means in its active position and then after a definite period to permit it to return to its normal position, and serving independently of the restoration of the controlling means to normal position, to suspend the valve opening action of the controlling means.

19. The combination of a source of fluid pressure; a normally closed valve controlling the flow of pressure fluid from said source to a sander; timing mechanism arranged to be put into action .to perform an operative cycle in which it opens said valve and then after a definite time interval closes the same; a brake valve; and two means selectively operable to put said timing mechanism into action, one of said two means being rendered into action, one of said two means being rendered active by said brake valve and the other being capable of manual actuation independently of the brake valve; and manually operable means for opening said normally closed valve and holding it open at will.

CHARLES A. CAMPBELL. 

